In recent years, a large number of bills are handled daily in banks, large-scale retailers, and the like, and a business of sorting and arranging these bills in accordance with the denomination or degree of defacement exists. As an apparatus configured to automate such an arrangement business of bills, a paper currency processing apparatus is proposed. This paper currency processing apparatus is provided with an inspection device configured to inspect types and the degree of defacement of bills, a plurality of accumulation storages in which inspected bills are classified into denominations or the like to be accumulated, a banding section configured to put a paper band around a bundle of bills, and the like.
The inspection device configured to optically inspect types of paper sheets is provided with a transfer mechanism configured to transfer paper sheets through an inspection position, a light source configured to irradiate the paper sheets transferred to the inspection position with inspection light, a photoreceptor configured to receive reflection light from the surface of the paper sheets, a standard plate arranged at the inspection position, and the like.
When the gain of the photoreceptor is to be set, the gain is adjusted by using reflection light from the standard plate as a criterion. When the standard plate of the inspection device is defaced, inspection results of the paper sheets are adversely affected. Thus, an apparatus in which an air nozzle is provided above a standard plate, and dust is prevented from adhering to the standard plate by blowing air onto the standard plate from above is proposed.
In the inspection device described above, at the time of inspection, when a paper sheet is transferred to the inspection position, the paper sheet covers the standard plate to hide the standard plate, and hence it is not possible to blow air onto the standard plate by using the air nozzle. Accordingly, during this time, dust cannot be blown away, dust, paper scraps and the like adhere to the standard plate, and the possibility of the standard plate being defaced is conceivable. Further, the paper sheets themselves come into contact with the standard plate, and the possibility of the paper sheets defacing the standard plate is conceivable.
On the other hand, although the paper sheets are attracted to a transfer belt and transferred to the inspection position, depending on the state of the paper sheets, they are transferred without being sufficiently attracted to the transfer belt. In this case, the paper sheets cannot be correctly transferred to the inspection position, thereby adversely affecting the inspection results.